Cleats are well-known devices which are used to attach flexible lines to objects such as ships masts.
Fishing weights are well-known devices which are used to control the position of fishing lines, baits, lures and nets.
Lead shot is presently used for angling, by crimping it on to a fishing line, but is causing damage to swans and wildfowl from lead poisoning. Alternatives to lead shot are often too hard to crimp on to fishing line without damaging either the weight or line. Soft non-toxic alternatives to lead shot which are capable of being crimped on to fishing line are non-transparent and often expensive.
Fishing weights having an axial hole are known. These are threaded on to a line, for use. A major disadvantage is that the hook must be removed from the line before such a weight can be removed or changed. It is desirable to avoid that disadvantage.